Development of a method for the determination of SCCPs (short-chain chlorinated paraffins) in bivalve mollusk using Soxtec device followed by gas chromatography-triple quadrupole tandem mass spectrometry

N Carro,A Mouteira,B Silva,I García,M Ignacio,J Cobas

doi:10.1186/s40543-018-0139-z

Abstract

BackgroundOrganochlorinated compounds are major environmental concern due to their persistence, long-range transportability and bio-accumulation. Chlorinated paraffin (CP) mixtures, especially short-chain CPs (SCCPs), are found in environmental samples at very high levels. However, information about their levels is still insufficient, mainly in marine biota.MethodsThis study aimed to optimize and validate a method for the determination of SCCPs (short-chain chlorinated paraffins) in bivalve mollusk using a Soxtec extractor and Gas Chromatography coupled with Mass Spectrometry in tandem GC-QqQ-MS/MS (EI). A Plackett-Burman (2^7*3/16) type III resolution factorial design was used to optimize the extraction and purification procedures, sample amount, extractant volume, boiling and rinsing times as extraction variables and alumina, acid silica gel amounts and elution volume as purification variables.ResultsThe most influent factors were sample amount, rinsing time, extractant volume and acid silica gel amount. Further experiments were performed in order to attain the optimal values of these factors (4 g sample amount, 50 mL n-hexane-dichloromethane as extractant volume, 2 and 1.5 h boiling and rinsing times, 8 g alumina, 4 g acid silica gel (15%) and 50 mL n-hexane-dichloromethane as elution solvent). Validation of the optimized method presented recoveries higher than 90% with RSD below 10%, showing good accuracy and precision. The whole method limits of detection and quantification were 46.13 mg Kg- 1 and 153.75 mg Kg- 1, respectively. This method was successfully applied to the analysis of wild mussel samples coming from two Galician Rías. The found levels were very low compared to other marine systems, below parts per million.ConclusionsThe main advantages of the optimized method lie in the rapidity and the low amount of sorbents and volume of solvent used, as well as the selectivity and sensitivity of triple quadrupole MS/MS.

Highlights

Organochlorinated compounds are major environmental concern due to their persistence, long-range transportability and bio-accumulation
SCCPs are of great interest due to their persistence, toxicological properties, and high octanol-water partition coefficient (Kow) that make them tend to bioaccumulate in lipid tissues of marine organisms and can be transferred and magnified along the food chain (Feo et al 2009; Yuan et al 2012)
Experimental design Since the number of variables potentially affecting the efficiency of the extraction and purification is very large, a screening factorial design Plackett-Burman (2^7*3/16) type III resolution at two levels has been applied

Summary

Introduction

Organochlorinated compounds are major environmental concern due to their persistence, long-range transportability and bio-accumulation. Chlorinated paraffin (CP) mixtures, especially short-chain CPs (SCCPs), are found in environmental samples at very high levels. Information about their levels is still insufficient, mainly in marine biota. Technical mixtures are used as extreme pressure additives in lubricants, flame retardants in plastics and paints, plasticizers in coatings, sealants and adhesives, and in leather fat liquors. They have replaced the PCBs uses in industrial mixtures (De Boer et al 2010). The western countries have begun to restrict the usage and production of CPs (van Mourik et al 2016)

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